x86, irq: Introduce two helper functions to support irqdomain map operation

Currently there are multiple entries to program IOAPIC pins, such as
io_apic_setup_irq_pin_once(), io_apic_set_pci_routing() and
setup_IO_APIC_irq_extra() etc.

This patch introduces two functions to help consolidate the code to
program IOAPIC pins. Function mp_set_pin_attr() is used to optionally
set trigger, polarity and NUMA node property for an IOAPIC pin.
If mp_set_pin_attr() is not invoked for a pin, the default configuration
from BIOS will be used.

Function mp_irqdomain_map() is an common implementation of irqdomain map()
operation. It figures out attribures for pin and then actually programs
the IOAPIC pin. We hope this will be the only entrance for programming
IOAPIC pin.

And the flow will:
1) caller such as xxx_pci_irq_enable figures out pin attributes.
2) Invoke mp_set_pin_attr() to set attributes for a pin. If the pin has
   already bin programmed,  mp_set_pin_attr() will aslo detects attribute
   confictions.
3) Invoke mp_map_pin_to_irq()
3.1) If IRQ has already been assigned, return irq_find_mapping()
3.2) Else irq_create_mapping()
		->irq_domain_associate()
			->mp_irqdomain_map()
				->io_apic_setup_irq_pin()

So every pin will only programmed once by mp_irqdomain_map(), so we
could kill io_apic_setup_irq_pin_once(), io_apic_set_pci_routing() and
setup_IO_APIC_irq_extra() etc.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1402302011-23642-30-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 3e4bea3a52b18..c535878685903 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -173,7 +173,9 @@ enum ioapic_domain_type {
 };
 
 struct device_node;
+struct irq_domain;
 struct irq_domain_ops;
+
 struct ioapic_domain_cfg {
 	enum ioapic_domain_type		type;
 	const struct irq_domain_ops	*ops;
@@ -192,6 +194,9 @@ extern u32 mp_pin_to_gsi(int ioapic, int pin);
 extern int mp_map_gsi_to_irq(u32 gsi, unsigned int flags);
 extern void __init mp_register_ioapic(int id, u32 address, u32 gsi_base,
 				      struct ioapic_domain_cfg *cfg);
+extern int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq,
+			    irq_hw_number_t hwirq);
+extern int mp_set_gsi_attr(u32 gsi, int trigger, int polarity, int node);
 extern void __init pre_init_apic_IRQ0(void);
 
 extern void mp_save_irq(struct mpc_intsrc *m);